Fuel feeding mechanism



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FUEL FEEDING MECHANI SM Filed June 17, 1941 8 Sheets-Sheet 1 Aug. 26,1947. w. M. FULTON FUEL FEEDING MECHANISM Filed Ju ne 17, 1941 8Sheets-Sheet 2 as IQZH 51b Aug. 26, 1947. w. M. FULTON FUEL FEEDINGHECHANISI Filed June 17, 1941 8 Sheets-Sheet 3 8 Sheets-Sheet 4 W. M.FULTON Filed June 17, 1941 FUEL FEEDING MECHANISM Aug. 26, 1947.

Aug. 26, 1947. w. M. FULTON FUEL FEEDING MECHANISM Filed June 17, 1941 8Sheets-Sheet 5 Zinvcntor M 1% W a attorneys Aug. 26, 1947.

W. M. FULTON FUEL FEEDING MECHANISM Filed June 17, 1941 8 Sheets-Sheet 6iqm ni ll- Zinnentor Aug 26, 1947. w. M. FULTON FUEL FEEDING MECHANISMFiled June 1'7, 1941 I 8 Sheets-Sheet 8 l l|lll\ l.\ llll lnllll Inllllll Patented Aug. 26, 1947 2,426,347 FUEL FEEDING MECHANISM Weston M.Fulton,

W. J. Savage Company, a corporation of Tennessee Application June 17,1941, Serial No. 398,500

r 17 Claims. (Cl. 110-101) This invention relates to an improvement infuel feeding mechanism of the character designed for the supply of coalor other solid fuel to heaters. This application is acontinuationin-part of my prior application on Stokers, Ser. No.359,794, filed October 4, 1940 now Patent Number 2,361,836, grantedOctober 31, 1944.

Experience has demonstrated the fact that where fuel is fed directly ontop of the fuel bed in a heater, it is difficult to obtain a fuel bedhaving a fairly level top surface. For instance, the stoker described inthe patents to Vodoz, Nos. 1,863,677 and 2,075,149, causes the fuel topile up in the center of the fuel bed, thus making the bed much thickerin its central portion than it is around the periphery thereof.

Furthermore, the largest and most immediate demand for stokers of thistype, is for use in heating plants that have employed hand firingheretofore, but a stoker to supply this demand, must be adaptable to awide variety of heaters. In many heaters, the fire-bowl is located at a.considerable distance back of the fire door which makes it necessary toconvey the fuel a substantial distance in the heater after it has beendeiivered at the fire door.

Various mechanical devices have been proposed heretofore foraccomplishing this purpose, but they have possessed objectionablecharacteristics. For instance, in Pierce patent,'No. 1,277,641, highpressure steam is used to blow the fuel from the fire door entrance intothe fire box. To be fairly successful, this method would require asource of high pressure steam, which is seldom if ever available inhouse heating plants, because, where steam is used as the heatingmedium, very low pressure of one or two pounds is used, and where hotwater or hot air is used, steam is not available at all.

' In the patent to Crosby, No. 888,875, a rotating wheel having radiallyextending blades is used to throw the fuel into the fire box, but thewheel is of the undershot type which requires the fuel to pass below theaxis of rotation and this results in clogging the feeder due to thedownward forcing of the fuel against the bottom of the feed trough thusallowing lumps to be caught between the descending blades of the wheeland the feed trough. If the rotation of the wheel be reversed so as tofeed the fuel in an overshot manner. then some of the fuel is wasted,gathers in the bottom of the fuel trough, and finally causes clogging.

The object of this invention is to improve the construction of thestoker of the class described,

Knoxville, Tenn., asaignor to Inc., Knoxville, Tenn.,

in which the objections heretofore encountered in connection withballistic fuel feeders are completely obviated permitting the practicalutilization of this type of stoker, and yet in a construction which canbe manufactured economically and used practically, and in whichprovision is made for securing an even distribution of the fuel over thefuel bed during feeding thereof into the heater.

A further object of the invention is to provide for the automaticcontrol of the feeding mechanism in response to the level of the fuel inthe chamber to which it is being fed, which is accomplished by thelocation of a feeler member in said chamber which is operated inresponse to the height or condition of the material therein to controlthe feeding action. Provision may be made for the operation of thisfeeler member in contact with the body of material in said chamber toaccomplish a leveling action thereof.

These objects are accomplished by the provision of a practical structureas hereinafter described, a preferred embodiment of which, together withmodifications thereof, are illustrated in the accompanying drawings, inwhich:

Fig. 1 is a side elevation of the preferred form of the invention shownapplied to a conventional form of heater;

Fig. 2 is a partial vertical sectional view therethrough, with parts inelevation;

Fig. 3 is a top plan view thereof;

Fig. 4 is a horizontal sectional view therethrough, on the line 4-4 ofFig. 2;

Fig. 5 is a detail vertical cross section on the line 5-5 of Fig. 2;

Fig. 6 is a detail elevation of the fuel leveling bar, taken on the line6-6 of Fig. 2;

Fig. 7 is a perspective view of the leveling rod supporting and guidingdevice, detached;

Fig. 8 is a perspective view of a ballistic fuel injector, detached;

Fig. 9 is a partial vertical sectional view through a modified form ofthe invention, parts being in elevation;

Fig. 10 is a detail cross section through the fuel spreading and controlmechanism, on the line Iii-ill of Fig. 9;

Fig. 11 is a detail cross section through the passageways of the feeder,taken on the line H--H of Fig. 9;

Fig. 12 is a detail cross section of a guide therefor, on the line 12-42of Fig. 9;

Fig. 13 is a partial vertical section through still type as desired.

another modified form of the invention. with parts in elevation;

Fig. 14 is a detail cross section of the air conducting tube thereof, onthe line ll-ll of Fig. 13; and

Fig. 15 is a vertical sectional view partly in elevation showing theinvention applied to the feeding of fuel to a supply bin.

The invention is shown in connection with a heater designated generallyby the numeral I, which may be of any conventional form to which it maybe desired to feed fuel by a stoker, such as a house heating furnace ofthe boiler or other ing the usual combustion chamber 2 therein adaptedto contain a fuel bed F to which fuel may be fed as desired through theusual opening 2 normally controlled by a fire door.

When the invention the opening 8, and is replaced by a frame 4 (Figs. 3and 4), which is secured to the heater by bolts 5. The frame I has twoseparate openings therein 6 and I, which are arranged in side-by-siderelation, and the opening 6 is covered by a small-sized fire door 8hinged to the frame I at 9 and provided with a latch to to hold the sameclosed. Upon opening the door 8, access may be had to the interior ofthe fire chamber 2 through the opening 6. The opening 1 is adapted toreceive the fuel feeding mechanism, as hereinafter described.

Referring to Figs. 1 and 2, a fuel hopper l l is arranged in front ofthe heater I, of a size to contain a predetermined quantity of fuel tosupply the heater for a substantial period of time. The hopper II has aback wall l2 behind which is provided an enlarged compartment l3 formedbetween a. bottom wall It and a top wall IS. A tubular extension l8projects from the compartment l3 through the opening 1 substantially tothe combustion chamber 2 of the heater, as shown in Figs. 2 and 4. Thetubular extension I6 is secured to the heater by means of the bolts 5.

This tubular extension I6 is shown in Fig. as rectangular in crosssection and has partitions l1 and I8 dividing the same into threesuperposed passageways IS, 20 and 2|, respectively, the purpose of whichwill be hereinafter described.

The hopper II has an upward extension 22 adlacent the back thereofwithin which are mounted interfltting twin screws 23, constituting aconveyor and constructed substantially as set forth in my prior patenton Feeder, No. 2,173,414, granted September 19, 1939. A baffle plate 24extends downward in the hopper II in front of A retention plate back ofthe conand is spaced from the back wall l2 of to allow fuel to 25extends vertically along the veyor 23,

The furnace I is shown as havthis being of any well-known construction.The speed reducer 30 has a high speed drive shaft II pulley 32 thereon,connected flanges 43 radially of the drum and cooperating with theflanges to form buckets or pockets therebetween.

the wheel H, so as .to deliver fuel to the top thereof, the upper end ofthe chut 45 being connected with the retention plate 25 at the upper endof the screw conveyor 23 to receive fuel therefrom. The fuel-injectingthe forward end of the passageway l9, but spaced therefrom.

Thus, when the fuel is elevated from the hopper i I by the twin screwconveyor 23 into the .upper end of the chute 45, it is dischargeddirectly onto the rotating wheel II. the pockets or buckets formed inthe periphery of the wheel between th blades 44, and due to the highspeed of rotation of the wheel, these blades exert a strong ballisticforce on the fuel to throw it tangentially from the wheel 4| throughonto the wheel at the proper point, the fuel can be thrown directlythrough the compartment l9 into the combustion chamber of the heater.

Heretofore, the ballistic type of feeders prothe wheel and its enclosinghousing, thus resulting in a clogging of the wheel which interferes withits proper rotation.

However, I have overcome this objection by placing the forward edge ofthe wheel 4| sufilciently far from the open end of the passageway I 8,as well as from the inclined wall ll of the compartment l3, to providea, liberal space therebetween so that all waste fuel which would nothave sufllcient force tating blades, to inject the same through thepassageway l9 into the combustion chamber of the heater, would havefreedom for return move- The fuel drops into ment along the inclinedwall l4, thence through the opening 28 into the hopper.

The waste fuel thus discharged into the hopper H is allowed to fallbetween the back wall of the hopper and the retention plate 25 to apoint where it is picked up again by the conveyor 23 along with theother fuel thus elevated during the feeding operation. As pointed outabove, the baiile 24 prevents the fuel from rising up around the bottomof the conveyor 23 sufficiently high so that it would prevent the freedischarge of the returned fuel through the opening 28 into the hopper.Furthermore, the action of the twin screws is such as .to keep the fuellevel very low at the opening 28, so as to accommodate this returnedfuel.

Located in passageway causing the fuel to be deflected uniformly overthe fuel bed F, as it is injected through the passageway l8 into thecombustion chamber. This mechanism is shown in Figs. 2 and 4, and isillustrated more in detail and claimed in my co-pending application onStokers, Ser. No. 359,794, filed October 4, 1940, now Patent Number2,361,836, granted October 31, 1944.

As shown, this deflecting means includes an arm 46 extending lengthwisethrough the passageway 20 being carried on an upstanding support 48 towhich it is pivotally connected at 48, as shown in Fig. 2. The arm 46extends from the passageway 20 into the combustion chamber 2 of theheater where its forward end is turned downward at 58. Rigidly fixed tothis inclined end 58 is a stationary baffle 5| (Fig. 4) to the oppositeedges of which side baffles 52 are hinged for vertical adjustingmovement relative thereto. The arm 48 is capable of vertical angularadjustment on its pivotal support 48 by screw 51, having threadedconnection with the inner end of said arm and rotatably adjustable bymechanism designated generally by the numeral 82.

Provision is made also for controlling the thickness of the fuel bed Fin the combustion chamber 2 of the heater, by means of arod 18 whichextends lengthwise through passageway 2|, as shown in Figs. 2-, 4 and 5,projeoting therefrom into the combustion chamber 2 of the heater. Theforward end of the rod 16 in the combustion chamber is down-turned at 11and screw-threaded, receiving the hub portion 18 of a stirrup 19thereon, which stirrup is adjustably connected 28 is mechanism for withthe down-turned end 11 for relative vertical adjustment and is adaptedto be locked in place thereon by a set screw 88. The lower end of thestirrup 18 carries a feeler in the form of a round bar 8| integraltherewith in position to contact the surface of the fuel in the heaterand to ride thereon.

The opposite end of the rod 18 has a ball and socket connection 82 witha lever arm 83 on a shaft 84. The lower end of the shaft 84 is journaledin a bearing carried by the partition |8, while the upper end thereofextends through the top l5 and has rigidly mounted thereon a crank 85.Pivotally connected at 88 with the outer end of the crank 85 (Fig. 3) isa link 81 which is pivotally connected at 88 with the gear 28. Thus,rotation of the gear 28 causes reciprocating movement of the link 81,oscillating the crank 85 and thereby imparting oscillatory movement tothe lever arm 83, thus swinging said lever arm and the inner end of therod 16 as shownin dotted lines in Fig. 4.

To provide for the lateral oscillatory movement of the rod 16 upon theoperation of the shaft 84, said rod is pivotally supported intermediateits ends in a guiding device shown in detail in Fig. '1. This guidingdevice is formed of a frame 88, having a pair of concave rollers 80journaled therein on pins 8|, spaced apart a distance sufficient toreceive and guide the rod 16 therebetween, which rod rides in theconcave peripheral grooves of the rollers. The rollers 80 reduce thefriction which would develop otherwise from the slight longitudinalmovement of the rod 18 due to the arc described by the lever arm 83 inoscillating said rod.

The frame 88 has axially aligned journal pins 82 and 83 extendingtherefrom. The journal pin 82 is journaled in the bottom of a well 84formed in the partition i8 (Fig. 2) into which the lower portion of theframe 88 extends. The journal pin 83 extends upward through the top |5in a which it is journaled, in alignment with a push button of a pushbutton electric switch 88. This switch 88 is of well-known constructionof the type used for controlling electric circuits, in which, howeverthe push button 85 breaks the circuit whenever it is depressed, while'release of the pressure causes it to close the electric circuitautomatically. The normally closed switch 86 is connected with a sourceof electrical supply through lines 81. while lines 88 extend from theswitch to the electric motor 35, whereby the switch 86 controls thesupply of current to the electric motor.

Provision is made also for manually controlling the supply of current tothe electric motor 35 independently-of the switch 88, for which purposeI have provided a switch 88 connected in parallel with the switch 88through wires I08 leading directly from the power lines 81 to the switch88, thence to the wires 88, as shown in Fig. 2. The switch 88 isconstructed for manual operation, and is adapted for use in testing theoperation of the stoker while adjusting the various working parts at thetime of installation. It is also of convenience if and when it shouldbecome necessary to remove large clinkers or other foreign matterthrough the fire door. By closing the switch 88, the operator closes thecircuit to the electric motor 35 operating the stoker mechanism, andthereby moving the round bar 8| to any desired position in thecombustion chamber 2, so that it will not interfere with his actions.When the round bar 8| has been moved 0 such desired position, out of theway of the operator, the opening of the switch 88 stops furthermovement.

Before putting the stoker in operation, it is first necessary to adjustthe fuel baiiies 5| and 52, so as to cause the fuel to spread evenlyover the fuel bed F.

Having adjusted the distribution of fuel over the grates of the heater,the device is ready for operation, and the manual switch 88 is opened,thereby stopping the electric motor 35, subject to the control of thecurrent thereto automatically under the control of switch 86.

Assuming that fire has been started in the heater but that the level ofthe fuel bed is at or below that shown in full lines in Fig. 2, the bar8| rests on top of the fuel bed, and by reason of its weight, said barwill pull downward on the rod 16, moving the guiding frame 88 to itslowermost position, such downward sliding movement being permitted bythe guiding of the pivot pins 8283. This moves the pin 83 out ofpressure. engagement with the switch button 85, permitting the switch 88to snap into a closed position, thus 7 supplying current from the wires91 to the wires 99 to energize the electric motor 35, operating themoving parts of the stoker mechanism as described above.

The oscillating movement of the rod I9, as indicated in dotted lines inFig. 4, causes the bar III to be dragged back and forth across the topof the fuel bed, leveling the surface of the fuel deposited thereon. Asadditional fuel is being injected into the combustion chamber, the topof the fuel bed rises gradually which lifts the bar 9| pushing the innerend of the rod I6 upward to the dotted line position in Fig. 2. Thisraises the guide 99-90 until the pivot pin 93 thereof presses upwardagainst the switch button 95 and the switch 99 snaps into open position,breaking the circuit to the electric motor 35, thus stopping theoperation of the stoker.

As the fire continues to burn, the consumption of fuel causes the top ofthe fuel bed to be lowered until the bar 8i is moved downward to thefull line position in Fig. 2, which will pull downward on the arm 19,lowering the guide 99-90 away from pressure engagement with the switchbutton 95, closing the circuit to the electric motor 35, and operatingthe stoker mechanism as described above.

The oscillatory movement of the rod 19 about the vertical. axis of theguide 99-90, as a fulcrum, with its inner end in the combustion chamber2, causes the round bar 9I to be dragged back and forth over the surfaceof the fuel bed F, as will be evident from Fig. 6, where the dotted linepositions represent the two extreme limits of the oscillation. The balland socket connection 92 permits of the slight twisting action of therod 19 caused by the parts 11, I9 in assuming the angular positionsindicated. The dragging of the round bar 9| back and forth over thesurface of the fuel bed I aids in maintaining this surface substantiallylevel and in distributing the fuel thereover.

It will be understood that the bar 9| can be adjusted to maintain thefuel bed of different thicknesses, by screwing it up or down on thethreaded portion I1 of the rod 16. After making such adjustment, the setscrew 90 is tightened to hold the stirrup I9, carrying the bar 9|, inits adjusted position on said rod, and with the axis of the bar 9|substantially in the direction shown in Fig. 2.

A modified form of the invention is shown in Figs. 9 to 12, which isespecially adaptable to installations where the height of the fire dooropening is relatively small as compared with its width, thus permittingthe hopper extension opening to be extended laterally relative to itsheight.

In this form of the invention, the hopper structure is shown asconstructed substantially identical with the construction illustrated inFigs. 1 to 8, as described above, but the tubular extension from thehopper, designated generally by the numeral I is divided by partitionsI02 and I03 into passageways I04, I05 and I 08. The passageway I05 isabove the passageway I04, while the passageway I06 is arranged at oneside thereof, as shown in Fig. 11. Fuel is injected through thepassageway I04 into the combustion chamber 2a from the ballistic fuelinjector 4Ia operated by the electric motor 35a as described above,which fuel is deflected in the combustion chamber 2a by bailie structuredesignated generally by the numeral I0I which corresponds with thatshown in Fig. 2, and which is supported by means extending through thepassageway I05.

and socket pivot H0 with the upper end of a walking beam III. Thewalking beam III is pivotally supported at H2 in a side of the hopperextension MI, in position to project at its upper end through the top ofsaid hopper extension. and with its lower end located adjacent thebottom thereof as shown in Fig. 9.

Mounted in the passageway I09 is a push rod verse bar I I4 is adapted tobear upon the top surface of the fuel bed and to be moved transverselythereof, as shown in Fig. 9.

The push rod II9 has a bifurcated rear end IIG, with a journal pin II'Imounted therein and adapted to support the rear end portion of the pushrod H3. The roller periphery which is received between two horijournalpin 1. This forms a pivotal connection between the walking beam III andthe push rod 3 which allows relative movement between these parts.

The push rod H9 is also supported and guided by a pair of spaced groovedrollers I22 which are journaled in a frame I23, forming a guide that isconstructed and operated substantially identical with the frame 99-90described above, except that the push rod I I9 is preferably rectangularin cross section as shown in Fig. 10, and therefore the grooves in therollers I22 are also rectangular instead of concave in cross section.Furthermore, the frame I23 has the pivot pins I24 and I2! thereofjournaled in opposite sides of a U-shaped frame I26 as shown in Fig. 10,which U-shaped frame also supports the push button switch I21 just abovethe end of the upper pivot pin I29. The U-shaped frame is supported onan adjusting screw I29 Joumaled in opposite sides of the pashandwheelI29 screw.

It will be evident that by turning the adjusting screw I29, the entiremechanism carried by the Since the rear end of the push rod H8 cannotmove vertically, being held in place between the 76 bars 9, this raisingand lowering of the. rollers her In. The dragging of the bar 9 I22 willcause the forward end of the push rod II3 to rise or fall, therebyadjusting the height of the bar H4 in the combustion chamber 2a, to varythe thickness or height of the fuel bed in the heater as may be desiredunder different conditions.

As shown in Fig. 9, the conducting wires pass through insulating sleevesI30 in the top wall of the hopper extension IM and have sufficient slackby coils within the passageway I06, so as to allow this verticalmovement of the switch I21 as the latter is adjusted up and down uponthe U-shaped frame I26.

Since the switch I21 is constructed, as described above in connectionwith the switch 06, so that pressure exerted on the push button thereofbreaks the electric circuit while release of this pressure allows theswitch to close the circuit, it will be evident that when the fuel levelin the combustion chamber 2a is sufficiently low to allow the bar I I4to pull downward on the forward end of the push rod II3, this will causethe guide frame I23 to move downward in the U-shaped frame I25, andthereby withdraw the pivot pin I25 from pressure engagement with thepush button of the switch I21. This allows the switch to close thecircuit and start the electric motor 35a.

The operation of the electric motor will drive the gearing includinggear 23a which will cause the link I03 to operate the walking beam Ill,thereby imparting reciprocating movement to the push rod '3. This willcause the bar H4 to be drawn back and forth across the top of the fuelbed in the combustion chamber, and at the same time, the injection wheel4Ia will be operated to feed fuel into the combustion chamber on top ofthe fuel bed as described above. This causes the fuel bed to build up,gradually raising the bar I I4 which moves on the surface thereof, thusgradually tilting the push rod I I3 higher until it forces the frame I23upward sufficiently to press the pivot pin I25 into pressure engagementwith the push button on the switch I21, operating the latter to breakthe electric circuit to the motor 35a.

As the fuel bed burns down and allows the bar II4 to pull downward onthe forward end of the push rod II3, the reverse operation takes place,and additional fuel is fed to the combustion cham- II4 back and forth onthe surface of the fuel aids in maintaining the top of the fuel bedlevel. This leveling member may be constructed of any desired shapesuitable for the purpose, a round bar, or a sphere, or the like.

Figs. 13 and 14 illustrate another modified form of the invention inwhich provision is made for cooling the fuel level control member, andalso showing a different form of fuel injector.

Mounted in the combustion chamber 2b of the heater is the fuel levelcontrol and feeler member I32, which is hollow and has a hollow tube I33connected therewith and supporting said member I32. The tube I33 iscircular in cross section, as shown in Fig. 14, and is divided by alongitudinal partition I34 into separate conduits or passageways I35 andI36 communicating at their lower ends with the interior of the memberI32.

A fitting I31 is secured to the top wall Ib with its open end incommunication with the atmosphere and is connected'with a flexible metalhose I38, leading to another fitting I39, which connects the same withthe upper end of passageway I35 for supplying air thereto.

The partition I34 extends only partway to. the upper end of the tubeI33, but said end is closed 0 by an end wall I40, inwardly of which, afitting I is connected with the tube I33 and with a flexible metal hoseI43 leading to a pipe I43 which passes upward through the wall I5b andis in open communication with smoke pipe I44 of the heater ID.

The closed end I40 of the tube I33 is rigidly attached to a rod I45which has a ball and socket connection 821) with an arm 83b of a shaft34b, which is operated from electric motor 35b in the manner describedabove in connection with Fig. 2. The tube I33 is rigid and is supportedand guided intermediate its ends by movably mounted rollers 90b, thefunction and manner of operation of which are substantially the same asthe corresponding parts described in connection with Fig. 2, while theoscillating movement of the tube I33 is substantially the same infunction and result as that of the rod 16 described. The flexible tubesI38 and I42 permit of this free oscillation.

The draft of the smoke pipe I44 is sufficient to impart a suction in thepipe I43 which sucks air through the fitting I31, hose I38, passagewayI35, down into and through the member G32, thence through passagewayI36, hose I42 and pipe I43 to the smoke pipe 4. This circulation ofrelatively cold air through the member $32 substantially reduces itstemperature and prevents it from becoming heated exclusively. This maybe desirable on large commercial boilers where forced draft producesvery high temperatures in the fuel bed which might prove injurious tothe member I32. 4

A blower may be used to supply air thereto, if found desirable, asindicated in dotted lines in Fig. 13, at I45, driven by the motor 351)and connected to the air inlet fitting I3'I through a tube I46. Thiswill increase the circulation of air through the passageways I35 and I35and thus more effectively cool the member I32.

The other structure of the stoker shown in Fig. 13 correspondssubstantially with that shown in Fig. 2, except that the injector wheelM is replaced with a ballistic type of injector usin a belt I4!extending over pulleys I48 and I43 mounted on shafts journaled inopposite sides of compartment I3b. The pulley I48 is driven by a beltI50 from the high speed shaft of the speed reducer 30b, as describedabove in connection with the injector M. The conveyor belt I41 hascleats I5I rigidly attached thereto by rivets or other fastenings forimparting injecting movement to the fuel.

The operation of this type of injector is substantially the same as theinjector 4!. The belt I41 is driven at high speed from the belt I50, andas the fuel is dropped onto the upper run thereof, it is struck by therapidly moving cleats I5I and injected through the passageway into thecombustion chamber 2b of the heater in the manner previously described.

The invention is shown in Fig. 15 as applied to mechanism for feedingfuel to the stoker hopper, where a separate bin feed is used.

In this connection, the mechanism for feeding the fuel to the heater issubstantially the same as described above, but a relatively small stokerhopper is used, as shown at No to which fuel is supplied from a storagebin I30 of relatively large size and capacity. A conveyor trough IBIextends from the bin I into the hopper No, for directing material fromthe bin into the hopper, having an open end in the latter. A spiralconveyor I62 extends through the trough 11 I6I being shown in the formof a conveyor screw on a shaft I63, which shaft has one end Journaled ina bearing I64 at the bottom of the bin I60, while its opposite endextends transversely across the hopper I I and is Journaled in a bearingI65 mounted in the wall 24c, of the hopper Ilc, with the extreme end ofsaid shaft projecting through the wall 24c.

A bevel pinion I66 fixed on said protruding end of the shaft I63 is inmesh with a bevel gear I61 fixed on a shaft I68 extending vertically inthe feeder screw compartment of the hopper I la, beside the wall 240.The lower end of the shaft I68 is journaled in a thrust bearing fixed inan arm I69 on a bracket I10 mounted on the wall 24c by bolts, rivets orother fastenings, the lower end of the shaft I68 extending through saidbearing as hereinafter described. The upper end portion of the shaft I68is journaled in a bearing I1I carried by a bracket I12 secured to theinner face of the hopper extension 220, with said shaft I68 projectingslightly through the bearing I1I.

A stub shaft I13 is arranged in axial alignment with the shaft I68,being journaled in a bearing I14 in the top of the hopper extension 220.A gear I15 fixed on the upper end of the stub shaft I'iii meshes withone of the gears 210 that drive the feeder screws as described above inconnection with Fig. 2, driven by a gear 29c from a speed reducer 30coperated by an electric motor 950, as described in connection therewith.Thus, the operation of the electric motor 350 to drive the feed screwsand supply fuel to the heater, also operates the stub shaft I13.

This stub shaft I13 carries a clutch member I16 in position forclutching engagement with a slidable clutch member I11, slidably keyedat I18 to the shaft I66 to move axially toward and from the clutchmember I16. The slidable clutch member I11 is adapted to be movedaxially relative to the shaft I68 by means of a fork I19 pivotallymounted at I80 on a bracket I 8| secured by rivets, bolts or otherfastenings to the hopper extension 220, externally thereof. The fork I19extends through an opening in the side of said hopper extension into thelatter, where one end of said fork engages the slidable clutch memberI11 for moving the latter toward the fixed clutch member I1'6 on theshaft I13, against the tension of a coiled spring I82 which isinterposed between said end portion of the fork I19 and the top of thehopper extension 220. The opposite end portion of the fork I19 ispivotally connected at I83 with a plunger rod I84 carrying a soft ironcore I85 of a solenoid I86. The solenoid I86 is supported on an arm I81attached to the bracket I8I and carried thereby.

The lower protruding end of the shaft I68 has fixed thereon a crank armI88. The free end of the crank arm I88 has a universal pivotalconnection I89 with one end of a connecting rod I90, the opposite end ofwhich connecting rod has a universal pivotal connection I9I with one endof a walking beam I92. The walking beam I 92 is pivotally supported atI93 intermediate its ends in one arm of a U-shaped bracket I94, whileits opposite end is pivotally connected with a rod I95 that extendssubstantially horizontally in the hopper He. The free end of the rod I95has suspended therefrom a feeler member in the form of a bar I96. Thebar I96 is adapted to be disposed substantially at the normal height ofthe fuel in the hopper lie.

The rod I extends siidably between rollers I91 in a frame I98 havingtrunnlons journaled in opposite sides of the U-shaped bracket I94,capable of turning movement and of bodily vertical movement relativethereto. The upper trunnion is in position to engage a switch button I99of an electric switch 200 of the normally closed type, as describedabove, which switch is mounted on the upper arm of the U-shaped bracketI94. Electric wires 2III are connected with the switch 200 and adaptedto be connected with a source of electrical energy, one of which wireshas the solenoid I86 connected in series therein, so that upon closingof the circuit through the switch 200, the solenoid I86 will beenergized. The wires "I extend through insulating bushings 202 in thetop of the hopper IIc.

The hopper He has a cover 203 hinged to the top thereof at 204 adaptedfor opening movement to gain access to this hopper and to the mechanismhoused therein.

The fuel is fed from the hopper He by stoker mechanism, such forinstance as has been described above, and normally the bar I96 rides onthe upper surface of the fuel in the hopper. When the fuel level islowered due to the feeding thereof by the stoker mechanism, the bar I96is gradually lowered, allowing the frame I98 to move downward andwithdrawing its upper trunnion from bearing engagement with the pushbutton I99 of the switch 200. When this Withdrawing action is suflicientto allow the switch 200 to close, the solenoid I86 is energized,attracting its core I85, swinging the fork I19 on its pivot I80, andpushing the clutch member I11 into clutch engagement with the member I16fixed on the stub shaft I13.

During the initial operation of the feeding mechanism for the stoker,the rotation of the feed screws by the gears 210 also rotates the gearI15 in mesh therewith and its stub shaft I13, but due to thedisengagement of the clutch members I16-I11, the shaft I68 and thefeeding mechanism operated thereby remains inoperative. However, uponengagement of the clutch members I16-I11, the shaft I68 is rotated,thereby driving the screw shaft I63 and operating the conveyor to feedfuel through the trough I6I from the bin The size and speed of the screwconveyor I62 are so arranged and predetermined that fuel will be fedfrom the bin I60 into the hopper He at a faster rate than it iswithdrawn from the hopper by the stoker feeding mechanism. Therefore,the fuel level in the hopper will rise gradually even as fuel is beingwithdrawn therefrom.

In the meantime, the crank the lower end of the shaft I 88 will operatethe walking beam I92 through the connecting rod I90, thus reciprocatingthe rod I95 and dragging the feeler bar I96 back and forth over thesurface of the fuel thus being fed in the hopper IIc. This continuesuntil the fuel level rises in the hopper sufficiently to lift the feelerbar I96 and its rod I95 sufllciently to push the upper trunnion of theframe I98 into pressure engagement with the switch push button I 99,thus breaking the circuit at the switch 200. This deenergizes thesolenoid I86 and allows the spring I82 to press downward on the innerend of the yoke I19, separating and disconnecting the clutch membersI16-I1I, thus stopping the operation of the shaft I68 and discontinuingthe I88 attached to I60 into the hopper I I0.

13 feeding of the fuel from the bin ISO to the hopper Ilc. When thelevel of the fuel in the hopper drops again sufficiently to close theswitch 200, the cycle of operations will be repeated.

I claim:

1. In feeding mechanism, the combination of a receptacle adapted toreceive a quantity of material therein, an elongated supporting deviceextending transversely of said receptacle and having a feeler suspendedtherefrom in position to bear upon the material in the receptacle, meansfor reciprocating said supporting device, guide means for directing thereciprocating movement of the supporting device while permittingtransverse bodily movement thereof, and means associated with said guidemeans and operable by the transverse bodily movement of the supportingdevice for controlling the feeding means.

2. In feeding mechanism, the combination of a receptacle adapted toreceive a quantity of fuel therein, means for feeding fuel to saidreceptacle, an elongated supporting member arranged to extend over thefuel in said receptacle and having a feeler bar carried thereby, meansfor actuating said supporting member to move the feeler bar back andforth over the fuel in the receptacle across the middle portion of saidreceptacle, movable guide means for said member, and means associatedwith said guide means and operable by movement thereof for controllingthe fuel feeding means.

3. In feeding mechanism, the combination of a receptacle adapted toreceive a quantity of material, electrically-actuated means for feedingmaterial to said receptacle, a supporting device extending into saidreceptacle and carrying a feeler thereon in position to bear upon thematerial in the receptacle, guide means for said supporting deviceconstructed for receiving the same and mounted for bodily movement inresponse to displacement of the feeler, operating means for thesupporting device, and means associated with the guide means andoperable thereby upon said bodily movement for controlling the feedingmeans.

4. In feeding mechanism, the combination of a receptacle adapted toreceive a quantity of material, electrically-actuated means for feedingmaterial to said receptacle, a supporting device extending into saidreceptacle and carrying a feeler thereon in position to bear upon thematerial in the receptacle, guide means for said sup porting devicereceiving the same therein and mounted for bodily movement in responseto displacement by the feeler, means for operating the supporting deviceto move the feeler back and forth in the receptacle, and switch meansassociated with the guide means in position for operation thereby uponbodily movement in response to displacement of the feeler forcontrolling the feeding means.

5. In feeding mechanism, the combination of a receptacle adapted toreceive a quantity of material therein, electrically-actuated means forfeeding material to said receptacle, a rod member extending laterallyinto said receptacle and having a feeler bar suspended therefrom inposition to bear upon the material in the receptacle, actuating meansconnected with said rod member for operating the same to move the feelerbar back and forth in the receptacle, a guide for said rod memberreceiving the same therethrough and guiding the movement thereof, meansmounting said guide for bodily movement in response to displacement ofthe rod member by the feeler bar, and electrical switching means forcontrolling the feeding means and arranged in position for operation bythe bodily movement of the guide.

6. In a stoker, the combination of fuel supply means, an elongatedsupporting member adapted to extend over a fuel bed and having means forbearing upon the fuel bed, means for moving said member back and forthsubstantially in a horizontal direction over the fuel bed, movable guidemeans for said member, and means operatively associated with said guidemeans and operable by movement thereof for controlling the fuel supplymeans.

7. In a stoker, the combination of fuel supply means, an elongatedsupporting member adapted to extend over a fuel bed and having means forbearing thereon, means for mounting said member for up and downmovement, means for moving said member back and forth substantially in ahorizontal direction, said mounting means including a guide for saidmember mounted for up and down movement with the member, and meansoperated by said guide in its up and down movement for controlling thefuel supply means.

8. In a heater having a combustion chamber with a fuel bed therein, thecombination of fuel supply means for said heater, 9. rod memberextending into the combustion chamber over the fuel bed and having aleveling member for bearing thereon, means for moving said rod memberback and forth substantially in a horizontal direction causing movementof the leveling member over the fuel bed, a guide for said rod membermounted for vertical movement therewith, and means operated by saidguide for controlling the fuel supply means.

9. In a heater having a combustion chamber with a fuel bed therein, thecombination of fuel supply means for-said heater, a rodmember extendinginto the combustion chamber over the fuel bed and having a levelingmember for bearing thereon, means for oscillating said rod member backand forth causing movement of the leveling member over the fuel bed, aguide for said rod member mounted for up and down movement with the rodmember, electrical power means for the fuel supply means, and a switchin position for actuation by the guide upon up and down movement thereoffor controlling said electrical power means.

10. In a heater having a combustion chamber with a fuel bed therein, thecombination of fuel supply means for said heater, a rod member extendinginto the combustion chamber over the fuel bed and having a levelingmember for bearing thereon, a guide for said rod member, means formounting said guide for turning movement and for up and down movementwith the rod member, electrical power means for driving the fuel supplymeans, means operatively connected with the power means and driventhereby for oscillating the rod member, and a switch electricallyconnected with the power means for controlling the same, said switchbeing associated with the guide in position for actuation thereby uponup and down movement thereof.

11. In a heater having a combustion chamber with a fuel bed therein, thecombination of fuel supply means for said heater, a rod member extendinginto the combustion chamber over the fuel bed and having a levelingmember for bearing thereon, a guide for said rod. member, means formounting said guide for up and down movement with the rod member,electrical power means for driving the fuel supply means, meansoperatively connected with the power means and driven thereby forreciprocating the rod member, and a switch electrically connected withthe power means for controlling the same, said switch being associatedwith the guide in position for actuation thereby upon up and downmovement thereof.

12. In a heater having-a combustion chamber with a fuel bed therein, thecombination of fuel supply means, a hollow control device in thecombustion chamber, means for circulating cooling air through saidhollow control device including rigid conduits supporting said controldevice and in communication at one end therethrough, means connectedwith said conduits and acting thereon to move the control devicesubstantially in a horizontal direction in the combustion chamber,flexible conduit means connected with the opposite end portions of theconduits for circulating air to and from. the same in differentpositions of the control device, and means actuated by the controldevice for controlling the fuel supply means.

13. In feeding mechanism, the combination with a receptacle adapted toreceive a quantity of material, of feeding means for depositing materialin said receptacle, and control means for said feeding means including afeeler member adapted to contact with the top of said material in thereceptacle, means for moving said feeler member back and forthsubstantially in a horizontal direction through the midportion of saidreceptacle, and means responsive to lifting movement of the feelermember by variations in the height of the material for regulating thefeeding means.

14. In feeding mechanism, the combination with a receptacle adapted toreceive a quantity of feeding material, of means for depositing materialdownwardly into the middle portion of said receptacle, and control meansfor said feeding means including a feeler member adapted to contact withthe top of said material in the receprtacle, means for reciprocatingsaid feeler member substantially in a horizontal direction through themiddle portion of the receptacle in position for contact with thematerial therein, and means responsive to lifting movement of the feeermember by variations in the height of the material for regulating thefeeding means.

15. In feeding mechanism, the combination with a receptacle adapted toreceive a quantity of material, of means for depositing material in saidreceptacle, and control means for said feeding means including a feelermember adapted to contact with the top of said material in thereceptacle, a support for said' feeler member extending transversely ofthe receptacle, mounting means for said support including a. guidetherefor and bodily movable by the support in response to variations inheight of the material in the receptacle, means for moving said supportbodily relative to said guide to move the feeler member back and forthsubstantially in a horizontal direction through the midportion of thereceptacle, and

means responsive to movement of said guide by the support for regulatingthe feeding means.

. therein, means mounting 16. In a, stoker, the combination with areceptacle adapted to receive a quantity of material therein, of meansfor feeding material to said receptacle, a devic in the receptacle inposition to bear upon the top portion of the material therein andmounted for transverse movement back and forth relative theretosubstantially in a horizontal direction, means mounting said device forbodily lifting movement in response to variations in the height of thematerial, and means operative in response to said lifting movement ofthe device for controlling the material feeding means.

17. In a stoker, the combination with a receptacle adapted to receive aquantity of solid fuel therein, of means for feeding fuel to saidreceptacle, a feeler member in the receptacle in position to bear uponthe top surface of the fuel said feeler member for transverse movementback and forth through the midportion of said receptacle substantiallyin a horizontal direction for leveling the material therein and forbodily vertical movement in response to variations in the height of thematerial, operating means for said feeler member for moving the sameback and forth, and means operative in response to said verticalmovements of the feeler member for controlling the fuel feeding means.

WESTON M. FULTON.

REFERENCE S CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 888,875 Crosby May 26, 19082,075,274 Darling Mar. 30, 1937 1,813,262 Snyder July 7, 1931 2,020,871Beers Nov. 12, 1935 1,863,677 Vodoz June 21, 1932 1,970,383 Lauterbur eta1 Aug. 14, 1934 2,045,357 Hoffman June 23, 1936 1,193,016 Heyl Aug. 1,1935 1,920,334 Williams Aug. 1, 1933 1,172,657 Young Feb. 22, 19162,155,607 Lippert 1 Apr. 25, 1939 680,818 Stones Aug. 20, 1901 869,708Hodgkinson Oct. 29, 1907 1,148,735 Young Aug. 3, 1915 2,271,236 SurdyJan. 27, 1942 224,237 Smith Feb. 3, 1880 2,075,149 Vodoz Mar. 30, 19372,125,926 Kalmbach Aug. 9, 1938 2,277,879 Ness et al Mar. 31, 19422,131,305 Shaw Sept. 27, 1938 1,862,477 Galusha June 7, 1932 1,970,523Hoffman Aug. 14, 1934 2,232,556 Nichols Feb. 18, 1941 1,173,693 WingenFeb. 29, 1916 1,970,858 Lauterbur et a1 Aug. 21, 1934 1,409,231 MurphyMar. 14, 1922 FOREIGN PATENTS Number Country Date 26,096 Austria Oct.25, 1906 22,569 Great Britain of A. D. 1891 463,003 Germany July 23,1928

